U.S. patent application number 15/545710 was filed with the patent office on 2018-01-18 for pre-treatment composition.
The applicant listed for this patent is Hewlett-Packard Development Company, L.P.. Invention is credited to Xulong Fu, Xiaoqi Zhou.
Application Number | 20180015764 15/545710 |
Document ID | / |
Family ID | 56615302 |
Filed Date | 2018-01-18 |
United States Patent
Application |
20180015764 |
Kind Code |
A1 |
Zhou; Xiaoqi ; et
al. |
January 18, 2018 |
PRE-TREATMENT COMPOSITION
Abstract
Disclosed herein is a pre-treatment composition that includes
aggregated nano-sized inorganic pigment particles, polymeric
organic particles having a particle size in a ratio of 100:1 to
1000:1 by comparison with the size of aggregated nano-sized
inorganic pigment particles, an ink absorber and a polymeric
binder. Also disclosed herein is a printable media that includes a
media substrate and the pre-treatment composition which is applied
to, at least, one side of the substrate; and the method for
obtaining it.
Inventors: |
Zhou; Xiaoqi; (San Diego,
CA) ; Fu; Xulong; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hewlett-Packard Development Company, L.P. |
Houston |
TX |
US |
|
|
Family ID: |
56615302 |
Appl. No.: |
15/545710 |
Filed: |
February 13, 2015 |
PCT Filed: |
February 13, 2015 |
PCT NO: |
PCT/US2015/015928 |
371 Date: |
July 23, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B41M 5/52 20130101; B41M
5/5218 20130101; C09D 129/04 20130101; B41M 5/5227 20130101; B41M
5/5254 20130101; C09D 7/61 20180101 |
International
Class: |
B41M 5/52 20060101
B41M005/52; C09D 129/04 20060101 C09D129/04; C09D 7/12 20060101
C09D007/12 |
Claims
1. A pre-treatment composition comprising aggregated nano-sized
inorganic pigment particles, polymeric organic particles having
particles size in a ratio of 100:1 to 1000:1 by comparison with the
size of aggregated nano-sized inorganic pigment particles, an ink
absorber and a polymeric binder.
2. The pre-treatment composition of claim 1 that further comprises
inorganic spacers.
3. The pre-treatment composition of claim 2 wherein the inorganic
spacers are particles that have an average particle size in the
range of about 0.1 to about 25 micrometers.
4. The pre-treatment composition of claim 1 wherein the aggregated
nano-sized inorganic pigment particles have an average particle
size in the range of about 1 to about 500 nanometers.
5. The pre-treatment composition of claim 1 wherein the aggregated
nano-sized inorganic pigment particles are present in an amount
representing from about 10 wt % to about 95 wt % of the total
weight of the pre-treatment composition.
6. The pre-treatment composition of claim 1 wherein the aggregated
nano-sized inorganic pigment particles are metal oxide or complex
metal oxide particles.
7. The pre-treatment composition of claim 1 wherein the aggregated
nano-sized inorganic pigment particles are titanium dioxide,
aluminum oxide or silicon dioxide.
8. The pre-treatment composition of claim 1 wherein the aggregated
nano-sized inorganic pigment particles are modified with a surface
treatment containing organosilane and aluminum chlorohydrate.
9. The pre-treatment composition of claim 1 wherein the polymeric
organic particles are present in the pre-treatment composition in
an amount representing from about 5 to about 20 parts based on 100
parts of aggregated nano-sized inorganic pigment particles.
10. The pre-treatment composition of claim 1 wherein the polymeric
organic particles are polyolefin particles, dispersion or emulsion
of polyolefin particles, acrylic emulsion or polyacrylic
emulsion.
11. The pre-treatment composition of claim 1 wherein the ink
absorber is a water soluble divalent or multi-valent metal
salt.
12. The pre-treatment composition of claim 1 wherein the ink
absorber is calcium chloride and/or calcium acetate.
13. The pre-treatment composition of claim 1 wherein the polymeric
binder is present, in the pre-treatment composition, in an amount
representing from about 2 to about 25 dry parts based on 100 parts
of aggregated nano-sized inorganic pigment particles.
14. A printable recording media comprising: a. a media substrate
and b. a pre-treatment composition applied to, at least, one side
of said substrate, that comprises aggregated nano-sized inorganic
pigment particles, polymeric organic particles having particles
size in a ratio of 100:1 to 1000:1 by comparison with the size of
aggregated nano-sized inorganic pigment particles, an ink absorber
and a polymeric binder.
15. A method of making a printable recording media comprising: a.
providing a media substrate; b. applying a pre-treatment
composition to, at least, one side of said substrate, that includes
aggregated nano-sized inorganic pigment particles, polymeric
organic particles having particles size in a ratio of 100:1 to
1000:1 by comparison with the size of aggregated nano-sized
inorganic pigment particles an ink absorber; and a polymeric
binder; c. and drying the pre-treatment composition in order to
obtain a coating layer and a printable recording media.
Description
BACKGROUND
[0001] Inkjet printing is a non-impact printing method in which an
electronic signal controls and directs droplets or a stream of ink
that can be deposited on a variety of substrates. Current inkjet
printing technology involves forcing the ink drops through small
nozzles by thermal ejection, piezoelectric pressure or oscillation,
onto the surface of a media. This technology has become a popular
way of recording images on various media surfaces, particularly
paper, for a number of reasons, including low printer noise,
capability of high-speed recording and multi-color recording.
Inkjet web printing is a technology that is specifically well
adapted for commercial and industrial printing. Example of such
printing technology is the "HP Page Wide Array printing" where more
than hundreds of thousand tiny nozzles on a stationary print-head
that spans the width of a page, delivering multi-colors ink onto a
moving sheet of paper under a single pass to achieve the super-fast
printing speed.
[0002] With these printing technologies, it is apparent that the
image quality of printed images is strongly dependent on the
construction of the recording media used. Pre-treatment
compositions or coatings can likewise be applied to various media
to improve printing characteristics and attributes of an image.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The drawings illustrate various embodiments of the present
recording media and are part of the specification.
[0004] FIGS. 1 and 2 are cross-sectional views of the printable
recording media according to embodiments of the present
disclosure.
[0005] FIG. 3 is a flow chart of a method for making a printable
recording media in accordance with an example of the present
disclosure.
DETAILED DESCRIPTION
[0006] The present disclosure refers to a pre-treatment composition
comprising aggregated nano-sized inorganic pigment particles,
polymeric organic particles having particles size in a ratio of
100:1 to 1000:1 by comparison with the size of aggregated
nano-sized inorganic pigment particles, an ink absorber and a
polymeric binder. The present disclosure refers also to a printable
recording media comprising a media substrate and the pre-treatment
composition as defined herein which is applied to, at least, one
side of the substrate in order to form a coated printable recording
media. The present disclosure refers also to the method for
obtaining it.
[0007] Before particular embodiments of the present disclosure are
disclosed and described, it is to be understood that the present
disclosure is not limited to the particular process and materials
disclosed herein. It is also to be understood that the terminology
used herein is used for describing particular embodiments only and
is not intended to be limiting, as the scope of protection will be
defined by the claims and equivalents thereof. In describing and
claiming the present article and method, the following terminology
will be used: the singular forms "a", "an", and "the" include
plural referents unless the context clearly dictates otherwise.
Concentrations, amounts, and other numerical data may be presented
herein in a range format. It is to be understood that such range
format is used merely for convenience and brevity and should be
interpreted flexibly to include not only the numerical values
explicitly recited as the limits of the range, but also to include
all the individual numerical values or sub-ranges encompassed
within that range as if each numerical value and sub-range is
explicitly recited. For example, a weight range of about 1 wt % to
about 20 wt % should be interpreted to include not only the
explicitly recited concentration limits of 1 wt % to 20 wt %, but
also to include individual concentrations such as 2 wt %, 3 wt %, 4
wt %, and sub-ranges such as 5 wt % to 15 wt %, 10 wt % to 20 wt %,
etc. All percent are by weight (wt %) unless otherwise indicated.
As used herein, "image" refers to marks, signs, symbols, figures,
indications, and/or appearances deposited upon a material or
substrate with either visible or an invisible ink composition.
Examples of an image can include characters, words, numbers,
alphanumeric symbols, punctuation, text, lines, underlines,
highlights, and the like.
[0008] The present disclosure refers to a pre-treatment
composition. Such pre-treatment composition, or treatment
composition, can be considered as a coating composition since it
can be applied to various media to improve, for example, printing
characteristics and attributes of an image. The phrase
"pre-treatment" refers to the process to apply a composition to a
printable recording media prior to printing application. In some
examples, the pre-treatment composition is a pre-treatment
composition that is going to be applied to an uncoated printable
recording media. By "uncoated", it is meant herein that the
printable recording media has not been treated or coated by any
composition after paper web is formed and dried at a paper machine.
Alternatively, "uncoated" also refers to the paper web which is
formed and dried on a paper machine and that is then treated with a
starch based solution known as "surface treatment or sizing" at a
paper machine. In some examples, the pre-treatment composition is a
pre-treatment composition that is going to be applied to a coated
printable recording media. By "coated", it is meant herein that the
printable recording media has been applied a composition prior to
apply a "pre-treatment" composition. It is noted that the term
"pre-treatment composition" refers to either a composition used to
form a coating layer as well as the coating layer itself, the
context dictating which is applicable. For example, a pre-treatment
composition or coating that includes an evaporable solvent is
referring to the compositional coating that is applied to a media
substrate. Once coated on a media substrate and after the
evaporable solvent is removed, the resulting coating layer can also
be referred to as a pre-treatment coating.
[0009] In some examples, the printable recording media, on which
the treatment composition will be applied, is an inkjet printable
media that comprise a substrate. The substrate can be specifically
designed to receive any inkjet printable ink, such as, for example,
organic solvent-based inkjet inks or aqueous-based inkjet inks
Examples of inkjet inks that may be deposited, established, or
otherwise printed on the printable substrate, include pigment-based
inkjet inks, dye-based inkjet inks, pigmented latex-based inkjet
inks and UV curable inkjet inks
[0010] The pre-treatment composition can be substantially colorless
and can be formulated to interact with the colorant and/or with
polymeric components of certain ink compositions. With the use of
such pre-treatment compositions, precipitated colorants deposited
on the surface of recording media can provide enhancement of image
quality. For example, improved optical density, improved durability
and high speed printing may be achieved with such pre-treatment
compositions. Alternatively, the pre-treatment composition can be
colored. Such colored pre-treatment composition can create some
special colored printing media such as blue drawing paper used
engineering design and drawing.
[0011] In some examples, the pre-treatment composition, when
applied to a printable recording media, will provide printed images
and articles that demonstrate excellent image quality (good bleed
and coalescence performance) while enabling high-speed and very
high-speed printing. By high-speed printing, it is meant herein
that the printing method can have a speed of 50 to 800 m/min or
higher (such as HP Web Press printers).
[0012] In some other examples, the pre-treatment composition, when
applied to printable recording media, provides printed images that
have, in the same time, an excellent gloss and a high absorptivity.
The images printed on the recording media are able to impart
excellent image quality: provides vivid color, such as higher gamut
and have a high degree of gloss, and high color density. High print
density and color gamut volume are realized with substantially no
visual color-to-color bleed and with good coalescence
characteristics. The pre-treatment composition, when applied to
printable recording media, provides printed images that have also
excellent durability.
[0013] In yet some other examples, the pre-treatment composition,
when applied to printable recording media, provides printed article
and image that have good dry time and fast absorption rate. By
"fast absorption rate", it is meant that the water, solvent and/or
vehicle of the ink can be absorbed by the media at a fast rate so
that the ink composition does not have a chance to interact and
cause bleed and/or coalescence issues. The absorption rate that
defects free printing is dependent on the speed of the printing and
amount of ink being used. The faster the printing speed and the
higher the amount of ink used, the higher is the demand on faster
absorption from the media.
[0014] FIG. 1 illustrates the printable recording media (100) as
described herein. The printable media (100) encompasses a base
substrate or media substrate or bottom supporting substrate (110)
and a coating layer (120) that result from the application of the
pre-treatment composition as described herein. The pre-treatment
composition is applied on, at least, one side of the substrate
(110) in order to from the coating layer (120). The pre-treatment
composition is thus applied on one side, i.e. the image side (101),
only and no other coating is applied on opposite side (102). In
some other examples, such as illustrated in FIG. 2, the
pre-treatment composition is applied to both opposing sides of the
substrate. The double-side coated media has thus a sandwich
structure, i.e. both sides of the substrate (110) are coated and
both sides may be printed. If the coated side is used as an
image-receiving side (101), the other side, i.e. backside (102),
may not have any coating at all, or may be coated with other
chemicals (e.g. sizing agents) or coatings to meet certain features
such as to balance the curl of the final product or to improve
sheet feeding in printer. FIG. 3 is a flow chart of a method for
making a printable recording media, where the pre-treatment
composition of the present disclosure is applied to a media
substrate in order to produce printable recording media in
accordance with an example of the present disclosure
[0015] The pre-treatment composition that is used to form the
coating layer (120) includes aggregated nano-sized inorganic
pigment particles, polymeric organic particles having particles
size in a ratio of 100:1 to 1000:1 by comparison with the size of
aggregated nano-sized inorganic pigment particles, an ink absorber
and a polymeric binder. In some examples, the pre-treatment
composition further comprises an inorganic spacer. The printable
media or printable recording media (100) comprises thus a media
substrate (110) and a pre-treatment composition or coating applied
thereon, on at least one side of the substrate, in order to form a
printable media, the pre-treatment composition comprising
aggregated nano-sized inorganic pigment particles, polymeric
organic particles having particles size in a ratio of 100:1 to
1000:1 by comparison with the size of aggregated nano-sized
inorganic pigment particles, an ink absorber and a polymeric
binder.
[0016] The pre-treatment composition comprises aggregated
nano-sized pigment particles. In some examples, the aggregated
nano-sized pigment particles are synthetic aggregated nano-sized
pigment particles. The word "synthetic" refers to small particles
that do not come from mechanical milling of mineral, rather from a
chemical precipitate procedure to generate nano-scale particles. In
some other examples, the aggregated nano-sized pigment particles
are nano-sized inorganic pigment particles. By "inorganic
particle", it is meant herein any particle which does not
chemically contain carbon or which contains carbon, where
applicable, in the form of carbonate or cyanide. The pigment
particles are nano-particles, which means that they are
"nano-sized" (nanometer-sized) pigment particles. The nano-sized
pigment particles are in the form of single particles that have an
average particle size in the nanometer range. However, due to
Brownian motion (or Pedesis motion), single particles are able to
collision with each other to form primary aggregated particles that
have an average particle size in the nanometer size (nm, 10.sup.-9
meter). The nano-sized inorganic pigment particles are thus
considered as aggregated nano-sized inorganic pigment particles. By
"aggregated", it is meant herein that the inorganic pigment
particles have an agglomeration structure: the particles are
aggregated and formed "primary aggregated particles". These primary
aggregated particles can further come together in order to form an
aggregated particle gel. The status of primary aggregated particles
can be achieved by chemical dispersion along with mechanical
dispersion. In some examples, the primary aggregated inorganic
nano-particles partially aggregate to form a "particle gel" (or
aggregated particle gel) have with average aggregated size of 20 to
100 nanometers (nm, 10.sup.-9 m). The primary aggregated particles
gel can have a special structure where many tiny holes are formed
during aggregation so that a nano-scale porous particle is formed.
The morphology of the aggregated primary particle gel can be in any
geometrical form such as spherical; rod-like, plate-like, cubic,
ellipsoid or other particle shapes. In some examples, the
aggregated particles are considered as substantially spherical.
[0017] In some examples, the aggregated nano-sized inorganic
pigment particles have an average particle size in the range of
about 1 to about 500 nanometer (nm). In some other examples, the
aggregated nano-sized inorganic pigment particles have an average
particle size in the range of about 2 to about 300 nanometer (nm).
The aggregated particle can also have a size in the range of about
20 to 100 nm as measured using laser diffraction spectroscopy but
avoiding larger percentage of un-aggregated particles which have
the size of 0.1 to 1 nm as measured by using x-ray
diffractometer.
[0018] The surface area of the aggregated inorganic pigment
particles can be in the range of about 20 to about 800 square meter
per gram or in the range of about 25 to about 350 square meter per
gram (gsm). The surface area can be measured, for example, by
adsorption using BET isotherm.
[0019] In some examples, the inorganic pigment particles are
pre-dispersed chemically in an acidic condition coupling with
mechanical mixing in a dispersed slurry form before being mixed
with the composition for coating on the substrate. An alumina
aggregate powder can be dispersed, for example, with high share
rotor-stator type dispersion system such as an Ystral system under
specific acidic condition.
[0020] In some examples, the pre-treatment composition contains
from about 10 wt % to about 95 wt % of aggregated nano-sized
inorganic pigment particles by total weight of the pre-treatment
composition. In some other examples, the pre-treatment composition
contains from about 40 wt % to about 85 wt % of aggregated
nano-sized inorganic pigment particles by total weight of the
pre-treatment composition.
[0021] In some examples, the nano-sized inorganic pigment particles
are metal oxide or complex metal oxide particles. As used herein,
the term "metal oxide particles" encompasses metal oxide particles
or insoluble metal salt particles. Metal oxide particles are
particles that have high refractive index (i.e. more than 1.65) and
that have particle size in the nano-range such that they are
substantially transparent to the naked eye. The visible wavelength
is ranging from about 400 to about 700 nm.
[0022] In some examples, the nano-sized inorganic pigment particles
are pseudo-boehmite, which is aluminum oxide/hydroxide
(Al.sub.2O.sub.3nH.sub.2O where n is from 1 to 1.5). In some other
examples, the nano-sized inorganic pigment particles are metal
oxide or semi-metal oxide that can include alumina which comprises
rare earth-modified boehmite, such as those selected from
lanthanum, ytterbium, cerium, neodymium, praseodymium, and mixtures
thereof. Commercially available alumina particles can also be used
and include, but not limited to, Sasol Disperal.RTM. HP10,
boehmite, and Cabot SpectrAl.RTM. 80 fumed alumina.
[0023] Examples of nano-sized inorganic pigment particles also
include, but are not limited to, titanium dioxide, hydrated
alumina, calcium carbonate, barium sulfate, silica, high brightness
alumina silicates, boehmite, pseudo-boehmite, zinc oxide, kaolin
clays, and/or their combination. The inorganic pigment can include
clay or a clay mixture. The inorganic pigment filler can include a
calcium carbonate or a calcium carbonate mixture. The calcium
carbonate may be one or more of ground calcium carbonate (GCC),
precipitated calcium carbonate (PCC), modified GCC, and modified
PCC. The inorganic particles that can also be selected from the
group consisting of aluminum oxide (Al.sub.2O.sub.3), silicon
dioxide (SiO.sub.2), nanocrystalline boehmite alumina (AlO(OH)) and
aluminum phosphate(AlPO.sub.4). In some other examples, the
inorganic particles are aluminum oxide (Al.sub.2O.sub.3) or silicon
dioxide (SiO.sub.2). Examples of such inorganic particles are
Disperal.RTM.HP-14, Disperal.RTM. HP-16 and Disperal.RTM. HP-18
available from Sasol Co. The nano-sized inorganic pigment particles
can also be silica or fumed silica particles. Examples of
commercially available fumed silica include Cab-O-SirLM-150,
Cab-O-Sil.RTM.M-5, Cab-O-Sil.RTM.MS-55, Cab-O-Sil.RTM.MS-75D,
Cab-O-Sil.RTM.H-5, Cab-O-Sil.RTM.HS-5, Cab-O-Sil.RTM.EH-5,
Aerosil.RTM. 150, Aerosil.RTM. 200, Aerosil.RTM. 300, Aerosil.RTM.
350 and Aerosil.RTM. 400.
[0024] In some examples, the nano-sized inorganic pigment particles
of the pre-treatment composition are titanium dioxide (TiO.sub.2),
aluminum oxide (Al.sub.2O.sub.3) or silicon dioxide (SiO.sub.2). In
some other examples, the nano-sized inorganic pigment particles can
have a chemical composition of Si.sub.4Mg.sub.3O.sub.10(OH).sub.2,
such as those commercially available under the trademark
Laponite.RTM. (from Southern Clay Products, Gonzales, Tex., USA) or
Optigel.RTM. SH (from Sud-Chemie; Louisville, Ky.).
[0025] The aggregate nano-sized inorganic pigment particles could
also be a "colloidal solution" or "colloidal sol". Said colloidal
sol is a composition that nano-sized particles with metal oxide
structure such as aluminum oxide, silicon oxide, zirconium oxide,
titanium oxide, calcium oxide, magnesium oxide, barium oxide, zinc
oxide, boron oxide, and mixture of two or more metal oxide. In some
examples, such as the colloidal sol is a mixture of about 10 to 20
wt % of aluminum oxide and about 80 to 90 wt % of silicon oxide. In
some examples, such as the colloidal sol is a mixture of about 14
wt % of aluminum oxide and about 86 wt % of silicon oxide. The
aggregate nano-sized inorganic pigment particles can be, in the
aqueous solvent, either cationically or anionically charged and
stabilized by various opposite charged groups such as chloride,
sodium ammonium and acetate ions. Examples of colloidal sol are
commercial available under the tradename Nalco.RTM.8676,
Nalco.RTM.1056, Nalco 1057, as supplier by NALCO Chemical Company;
or under the name Ludox.RTM./Syton.RTM. such as Ludox.RTM. HS40 and
HS30, TM/SM/AM/AS/LS/SK/CL-X and Ludox.RTM. TMA from Grace Inc.; or
under the name Ultra-Sol 201A-280/140/60 from Eminess Technologies
Inc. The colloidal sol can also be prepared by using particles
agglomerates which have the chemical structure as descripted above
but which have starting particles size in the range of about 5 to
10 micrometer (10.sup.-6 meters). Such colloidal sol can be
obtained by breaking agglomerates using chemical separation and
mechanical shear force energy. Monovalent acids such as nitric,
hydrochloric, formic or acetic with a PKa value of 4.0 to 5.0 can
be used. Agglomerates are commercial available, for example, from
Sasol, Germany under the tradename of Disperal.RTM. or from
Dequenne Chimie, Belgium under the Dequadis.RTM.HP.
[0026] The aggregate nano-sized inorganic pigment particles can be
treated with acetic acid in order to adjust the pH to the range 3.5
to 5.5, and can then be dispersed using high share Rotor-stator
system such as Kadi.RTM.mill or Ystral.RTM. system.
[0027] The primary aggregated inorganic pigment particles can be
modified into synthetic organic-inorganic particles, meaning that
synthetic inorganic particles can be underwent a surface treatment
with organic compounds with functional groups. The inorganic
nanoparticles may also be surface modified, depending on the
particular type of composition involved and stability requirement.
In some examples, the organic compound with functional groups are
organosilanes. Organosilane can be represented by the general
formula Y--R--Si--X.sub.3 where X is a hydrolysable alkoxy group
such as methoxy and ethoxy, and Y is an organo-functional group
such as amino, vinyl, expoxy-methacryl. The group Y is connected
with silicon via an alkyl bridge as represented by R in the
formula. In a neutral to acidic environment, the X group and the
alkoxy groups are able to react with the surface groups of
inorganic fillers. The reaction is firstly hydrolization to
generate silane triol, and silanol groups then condense with oxide
or hydroxyl group on the filler surface. The neighboring siloxane
chains can interact further to eventually form a polysiloxane layer
at the particle surface.
[0028] Examples of organosilane include
gamma-amino-propyl-triethoxy silane, mono-amino silane, diamino
silane, triamino silane,
bis(2-hydroethyl)-3-amino-propyl-triethoxysilane,
3-mercapto-propyl-trimethoxysilane,
3-glycidoxy-propyl-trimethoxysilane,
bis(triethoxy-silylpropyl)disulfide,
3-amino-propyl-triethoxysilane, bis-(trimethoxy-silyl-propyl)amine,
N-phenyl-3-aminopropyltrimethoxysilane,
N-aminoethyl-3-aminopropylmethyldimethoxysilane, 3
-ureido-propyl-trimethoxysilane, 3
-methacryl-oxypropyl-trimethoxysilane,
N-(trimethyl-oxy-silylpropyl)isothiouronium chloride,
N-(triethoxy-silpropyl)-O-polyethylene oxide,
3-(triethoxy-silyl-propyl succinic anhydride, or
3-(2-imidazolin-1-yl)propyl-tri-ethoxy-silane,
3-aminopropyltrimethoxysilane,
N-(2-aminoethyl-3-aminopropyltrimethoxysilane,
3-(triethoxy-silylpropyl)-diethylenetriamine,
poly(ethyleneimine)trimethoxysilane, amino-ethylamino-propyl
trimethoxysilane, or amino-ethylamino-ethyl-amino-propyl
trimethoxysilane.
[0029] The aggregated nano-sized inorganic pigment particles can be
also modified with inorganic surface treatment compounds and/or
with organic compounds with functional groups. An example of
inorganic treatment compounds includes aluminum chlorohydrate. The
organosilane reagent can be reacted with aluminum chlorohydrate. In
some examples, the aggregated nano-sized inorganic pigment
particles are modified with a surface treatment containing
organosilane and aluminum chlorohydrate.
[0030] The organosilane and the aluminum chlorohydrate can function
together to treat the metal oxide or semi-metal oxide, e.g. fumed
silica, from being negatively charged to being cationically
charged. It has been recognized that good printing results, as well
as good adhesion can be obtained when aluminum chlorohydrate (ACH)
is reacted with aminosilane coupling agent first in an aqueous
medium to form a complex of sorts. In one preparatory example, such
"complex" is believed to be formed by a covalent bonding with the
surface of aggregated nano-sized inorganic pigment particles, and
the powder of aggregated nano-sized inorganic pigment particles can
then be dispersed into an aqueous solution comprising the adduct of
aluminum chlorohydrate and an aminosilane. When included, the
aluminum chlorohydrate can be reacted with the organosilane reagent
at a weight ratio of aluminum chlorohydrate to organosilane of 1:10
to 5:1.
[0031] The pre-treatment composition may further, optionally,
comprise inorganic spacers. In some examples, the inorganic spacer
is part (i.e. included) of the aggregated nano-sized inorganic
pigment particle system. Thus, with regard to aggregate nano-sized
inorganic pigment particles, the pre-treatment composition may
further include second particles (i.e. inorganic spacer) that have
a size range that is at least 5 times bigger than the size of the
first nano-particles (i.e. aggregate nano-sized inorganic pigment
particles). Without being linked by any theory, it is believe that
with addition of small amount of inorganic spacers, the direct
collision of the aggregate nano-sized inorganic pigment particles
will be reduced and therefore the stability and particle size of
inorganic particles can be controlled. The inorganic spacer
particles can be thus added in order to improve the stability of
the dispersion of the aggregate nano-sized inorganic pigment
particles.
[0032] The inorganic spacers are particles that have larger
particle size compared with aggregated nano-sized inorganic pigment
particles, with a ratio of 5:1 to 200:1 (by comparison with the
size of aggregated nano-sized inorganic pigment particles). Which
means that, in some examples, the inorganic spacers are particles
that have an average particle size in the range of about 0.1 to
about 25 micrometers (um, 10.sup.-6m). In some other examples, the
inorganic spacers are particles that have an average particle size
in the range of about 1 to about 10 micrometers (.mu.m). In some
examples, the ratio, by weight, of inorganic spacer compared with
aggregated nano-sized inorganic pigment particles ranges from 1:300
to 1:1500.
[0033] Examples of inorganic spacers include but are not limited
to, calcium carbonate, zeolite, silica, talc, alumina, aluminum
trihydrate (ATH), calcium silicate, kaolin, calcined clay, and
combination or mixtures of any of these. Examples of inorganic
spacer particles, also includes, but are not limited to, ground
calcium carbonate such as Hydrocarb.RTM. 60 available from Omya,
Inc.; precipitated calcium carbonate such as Opacarb.RTM.A40 or
Opacarb.RTM.3000 available from Specialty Minerals Inc. (SMI); clay
such as Miragloss.RTM. available from Engelhard Corporation;
synthetic clay such as hydrous sodium lithium magnesium silicate,
such as, for example, Laponite.RTM. available from Southern Clay
Products Inc., and titanium dioxide (TiO.sub.2) available from, for
example, Sigma-Aldrich Co. Examples of inorganic spacer particles
include, but are not limited to, particles, either existing in a
dispersed slurry or in a solid powder, of polystyrene and its
copolymers, polymethacrylates and their copolymers, polyacrylates
and their copolymers, polyolefins and their copolymers, such as
polyethylene and polypropylene, a combination of two or more of the
polymers. The inorganic spacer particles may be chosen from silica
gel (e.g., Silojet.RTM.703C available from Grace Co.), modified
(e.g., surface modified, chemically modified, etc.) calcium
carbonate (e.g., Omyajet.RTM.B6606, C3301, and 5010, all of which
are available from Omya, Inc.), precipitated calcium carbonate
(e.g., Jetcoat.RTM.30 available from Specialty Minerals, Inc.), and
combinations thereof.
[0034] The pre-treatment composition comprises polymeric organic
particles. By "organic particle", it is meant herein that a
particle that has natural and synthetic compounds of high molecular
weight consisting of hydrogen-carbon back bone chain structure such
as linear polyethylene, polypropylene and cyclic polystyrene. By
"polymeric", it is meant herein that the organic particles can be
in any polymeric bond chain structure for example, polyolefin like
polyethylene and copolymers, polypropylene and copolymers,
poly-wax, poly-paraffin, polyacrylic and copolymers,
polymethacrylic and copolymers, polystyrene and copolymers,
polyurethanes and copolymers.
[0035] In some examples, the polymeric organic particles have a
size, compared to the size of the aggregated nano-sized inorganic
pigment particles, in a ratio of 100:1 to 1000:1. Thus, in some
examples, the average particle size of the polymeric organic
particle is from about 0.1 .mu.m to about 50 .mu.m; in some other
examples, from about 0.5 .mu.m to about 10 .mu.m; in yet some other
examples, from about 1 .mu.m to about 5 .mu.m.
[0036] In some examples, the polymeric organic particles are
present in the pre-treatment composition in an amount representing
from about 5 to about 20 parts based on 100 parts of aggregated
nano-sized inorganic pigment particles.
[0037] The polymeric organic particles can be present, in the
pre-treatment composition, under any morphology such as solid
particles or hollow particles, or particles with core-shell
structure. The electric charge of the particles can be any kind but
in some examples, they are positively charged or non-ionic
charged.
[0038] The polymeric organic particles may have an average
molecular weight (Mw) of about 5,000 to about 500,000. In some
examples, the polymeric organic particles have an average molecular
weight (Mw) ranging from about 100,000 to about 300,000. In some
other examples, the polymeric organic particles have an average
molecular weight of about 250,000.
[0039] In some examples, the polymeric organic particles are
polyolefin particles, dispersion or emulsion of polyolefin
particles, acrylic emulsion or polyacrylic emulsion. The polymeric
organic particles can be polyolefin particles or dispersion or
emulsion of polyolefin particles such as polyethylene and
polypropylene particles such as the ones commercial available from
BYK Ltd with tradename of Polyemulsion10A30.RTM.,
polyemulsion10G38SP.RTM., polyemulsion10N40.RTM. and
Polyemulsion316G30SP.RTM.; Luwax.RTM. or Poligen.RTM. serials wax
from BASF; and Ultralube.RTM. serials wax from Keim-Additec Co. The
polymeric organic particles can also be acrylic emulsion or
polyacrylic emulsion. The polymeric organic particles can be chosen
among the group consisting of styrene, acrylic, styrene/acrylics,
vinyl/acetate, polyacrylics, methacrylates and combinations
thereof. In some examples, the polymeric organic particles can be
polystyrene latex polymers. In some other examples, the polymeric
organic particles are plastic pigment slurry of styrene/butadiene
emulsion copolymers. Examples of polymeric organic particles that
can be used in accordance with embodiments of the present invention
include Ropaque.RTM.BC-643, Ropaque.RTM.HP-543, or
Ropaque.RTM.OP-84 (all manufactured by Rohm and Haas Company, USA)
and HS-3000NA or HS-3020NA (available from The Dow Chemical
Company, USA). Other specific examples of these polymers may
include, a styrene acrylic emulsion polymer sold under the trade
name Raycat.RTM. 29033, a polyacrylic emulsion polymer sold under
the trade name Raycat.RTM.78, and an acrylic emulsion polymer sold
under the trade name Raycryl.RTM. 30S available from Specialty
Polymers, Inc.
[0040] The pre-treatment composition comprises an ink absorber. The
ink absorber can be present, in the pre-treatment composition, in
an amount representing from about 0.05 to about 5 dry parts based
on 100 parts of aggregated nano-sized inorganic pigment
particles.
[0041] Without being linked by any theory, it is believed that the
function of the ink absorber is to be able to separate the colorant
(pigment or dye) contained in the ink composition from ink vehicle
of the ink composition applied to the printable media and then
chemical bonding the ink pigment or dye. The ink absorber can be
considered as an "electrical charged" compound. "Electrical
charged" refers to chemical substance with some atoms gaining or
losing one or more electrons or protons, together with a complex
ion consists of an aggregate of atoms with opposite charge. The
electrical charged substance is a charged ion or associated complex
ion that can de-coupled in an aqueous environment. In some
examples, the electrical charged substance is an electrolyte,
having a low molecular species or a high molecular species.
[0042] In some examples, the ink absorber is a water soluble salt.
The term "water soluble" is meant to be understood broadly as a
species that is readily dissolved in water. Thus, water soluble
salts may refer to a salt that has a solubility greater than 15
g/100 g H.sub.2O at 1 Atm. pressure and at 200.degree. C. The
electrical charged substance can be a water soluble metallic salt
that can be an organic salt or an inorganic salt. The electrical
charged substance can be an inorganic salt; in some examples, the
electrical charged substance is a water-soluble and multi-valent
charged salts. Multi-valent charged salts include cations, such as
Group I metals, Group II metals, Group III metals, or transition
metals, such as sodium, calcium, copper, nickel, magnesium, zinc,
barium, iron, aluminum and chromium ions. The associated complex
ion can be chloride, iodide, bromide, nitrate, sulfate, sulfite,
phosphate, chlorate, acetate ions.
[0043] The ink absorber can be an organic salt; in some examples,
the ink absorber is a water-soluble organic salt. Organic salt
refers to associated complex ion that is an organic species, where
cations may or may not the same as inorganic salt like metallic
cations. Organic metallic salt are ionic compounds composed of
cations and anions with a formula such as
(C.sub.nH.sub.2n+1COO.sup.-M.sup.+)*(H.sub.2O).sub.m where M.sup.+
is cation species including Group I metals, Group II metals, Group
III metals and transition metals such as, for example, sodium,
potassium, calcium, copper, nickel, zinc, magnesium, barium, iron,
aluminum and chromium ions. Anion species can include any
negatively charged carbon species with a value of n from 1 to 35.
The hydrates (H.sub.2O) are water molecules attached to salt
molecules with a value of m from 0 to 20. Examples of water soluble
organic salts include metallic acetate, metallic propionate,
metallic formate, metallic oxalate, and the like. The organic salt
may include a water dispersible organic salt. Examples of water
dispersible organic salts include a metallic citrate, metallic
oleate, metallic oxalate, and the like.
[0044] In some examples, the ink absorber is a water soluble,
divalent or multi-valent metal salt. Specific examples of the
divalent or multi-valent metal salt used include, but are not
limited to, calcium chloride, calcium acetate, calcium nitrate,
calcium pantothenate, magnesium chloride, magnesium acetate,
magnesium nitrate, magnesium sulfate, barium chloride, barium
nitrate, zinc chloride, zinc nitrate, aluminum chloride, aluminum
hydroxychloride, and aluminum nitrate. Divalent or multi-valent
metal salt might also include CaCl.sub.2, MgCl.sub.2, MgSO.sub.4,
Ca(NO.sub.3).sub.2, and Mg(NO.sub.3).sub.2, including hydrated
versions of these salts. In some examples, the water soluble
divalent or multi-valent metal salt can be selected from the group
consisting of calcium acetate, calcium acetate hydrate, calcium
acetate monohydrate, magnesium acetate, magnesium acetate
tetrahydrate, calcium propionate, calcium propionate hydrate,
calcium gluconate monohydrate, calcium formate and combinations
thereof. In some examples, the ink absorber is calcium chloride
and/or calcium acetate. In some other examples, the ink absorber is
calcium chloride. In some examples, the ink absorber is a high
molecular charged substance that includes, but that is not limited,
polyaluminum chloride, polyaluminum chlorosulphate, polyaluminum
silicosulphate, polydiallyldimethylammonium chloride, quaternary
polyamines, poly(styrenesulfonic acid) and dicyandiamide
resins.
[0045] In some examples, the ink absorber can co-exist with other
components in the pre-treatment composition. The pre-treatment
layer or coating layer can, therefore, exist as the single layer on
the outmost side of the supporting substrate. In some other
examples, multiple layers exist on the treatment/coating structure.
In some examples, a treatment/coating structure can include a
separated ink absorber layer that is sandwiched between the
substrate and main composite of the pre-treatment composition. In
some other examples, the ink absorber can create a separate layer
that is on the top of the pre-treatment composite, i.e. outmost of
the printing media.
[0046] The pre-treatment composition comprises a polymeric binder.
The polymeric binder can be present, in the pre-treatment
composition, in an amount representing from about 2 to about 25 dry
parts based on 100 parts of aggregated nano-sized inorganic pigment
particles.
[0047] The polymeric binder can be either water a soluble, a
synthetic or a natural substances or an aqueous dispersible
substance like polymeric latex. In some other examples, the
polymeric binder is polymeric latex. The polymeric binder can be a
water soluble polymer or water dispersible polymeric latex. The
binder may be selected from the group consisting of water-soluble
binders and water dispersible polymers that exhibit high binding
power for base paper stock and pigments, either alone or as a
combination. In some examples, the polymeric binder components have
a glass transition temperature (Tg) ranging from -10.degree. C. to
+50.degree. C. The way of measuring the glass transition
temperature (Tg) parameter is described in, for example, Polymer
Handbook, 3rd Edition, authored by J. Brandrup, edited by E. H.
Immergut, Wiley-Interscience, 1989.
[0048] Suitable polymeric binder include, but are not limited to,
water soluble polymers such as polyvinyl alcohol, starch
derivatives, gelatin, cellulose derivatives, acrylamide polymers,
and water dispersible polymers such as acrylic polymers or
copolymers, vinyl acetate latex, polyesters, vinylidene chloride
latex, styrene-butadiene or acrylonitrile-butadiene copolymers.
Non-limitative examples of suitable binders include styrene
butadiene copolymer, polyacrylates, polyvinylacetates, polyacrylic
acids, polyesters, polyvinyl alcohol, polystyrene,
polymethacrylates, polyacrylic esters, polymethacrylic esters,
polyurethanes, copolymers thereof, and combinations thereof. In
some examples, the binder is a polymer and copolymer selected from
the group consisting of acrylic polymers or copolymers, vinyl
acetate polymers or copolymers, polyester polymers or copolymers,
vinylidene chloride polymers or copolymers, butadiene polymers or
copolymers, styrene-butadiene polymers or copolymers,
acrylonitrile-butadiene polymers or copolymers. In some other
examples, the binder component is a latex containing particles of a
vinyl acetate-based polymer, an acrylic polymer, a styrene polymer,
an SBR-based polymer, a polyester-based polymer, a vinyl
chloride-based polymer, or the like. In yet some other examples,
the binder is a polymer or a copolymer selected from the group
consisting of acrylic polymers, vinyl-acrylic copolymers and
acrylic-polyurethane copolymers. Such binders can be
polyvinylalcohol or copolymer of vinylpyrrolidone. The copolymer of
vinylpyrrolidone can include various other copolymerized monomers,
such as methyl acrylates, methyl methacrylate, ethyl acrylate,
hydroxyethyl acrylate, hydroxyethyl methacrylate, ethylene,
vinylacetates, vinylimidazole, vinylpyridine, vinylcaprolactams,
methyl vinylether, maleic anhydride, vinylamides, vinylchloride,
vinylidene chloride, dimethylaminoethyl methacrylate, acrylamide,
methacrylamide, acrylonitrile, styrene, acrylic acid, sodium
vinylsulfonate, vinylpropionate, and methyl vinylketone, etc.
Examples of binders include, but are not limited to, polyvinyl
alcohols and water-soluble copolymers thereof, e.g., copolymers of
polyvinyl alcohol and poly(ethylene oxide) or copolymers of
polyvinyl alcohol and polyvinylamine; cationic polyvinyl alcohols;
aceto-acetylated polyvinyl alcohols; polyvinyl acetates; polyvinyl
pyrrolidones including copolymers of polyvinyl pyrrolidone and
polyvinyl acetate; gelatin; silyl-modified polyvinyl alcohol;
styrene-butadiene copolymer; acrylic polymer latexes;
ethylene-vinyl acetate copolymers; polyurethane resin; polyester
resin; and combination thereof. Examples of binders include
Poval.RTM.235, Mowiol.RTM.56-88, Mowiol.RTM.40-88 (products of
Kuraray and Clariant).
[0049] The polymeric binder may have an average molecular weight
(Mw) of about 5,000 to about 500,000. In some examples, the binder
has an average molecular weight (Mw) ranging from about 100,000 to
about 300,000. In some other examples, the binder has an average
molecular weight of about 250,000. The average particle diameter of
the latex binder can be from about 10 nm to about 10 .mu.m; in some
other examples, from about 100 nm to about 5 .mu.m; and, in yet
other examples, from about 500 nm to about 0.5 .mu.m. The particle
size distribution of the binder is not particularly limited, and
either binder having a broad particle size distribution or binder
having a mono-dispersed particle size distribution may be used. The
binder may include, but is in no way limited to latex resins sold
under the name Hycar.RTM. or Vycar.RTM. (from Lubrizol Advanced
Materials Inc.); Rhoplex.RTM. (from Rohm & Hass company);
Neocar.RTM. (from Dow Chemical Comp); Aquacer.RTM. (from BYC Inc)
or Lucidene.RTM. (from Rohm & Haas company).
[0050] In some examples, the polymeric binder is selected from
natural macromolecule materials such as starches, chemical or
biological modified starches and gelatins. The binder could be a
starch additive. The starch additive may be of any type, including
but not limited to oxidized, ethylated, cationic and pearl starch.
In some examples, the starch is used in an aqueous solution.
Suitable starches that can be used herein are modified starches
such as starch acetates, starch esters, starch ethers, starch
phosphates, starch xanthates, anionic starches, cationic starches
and the like which can be derived by reacting the starch with a
suitable chemical or enzymatic reagent. In some examples, the
starch additives can be native starch, or modified starches
(enzymatically modified starch or chemically modified starch). In
some other examples, the starches are cationic starches and
chemically modified starches. In yet some other examples, the
starch is used in a form of nano-sized dispersed slurry. Useful
starches may be prepared by known techniques or obtained from
commercial sources. Examples of suitable starches include Penford
Gum-280 (commercially available from Penford Products), SLS-280
(commercially available from St. Lawrence Starch), the cationic
starch CatoSize 270 (from National Starch) and the hydroxypropyl
No. 02382 (from Poly Sciences). In some examples, a suitable size
press/surface starch additive is 2-hydroxyethyl starch ether, which
is commercially available under the tradename Penford.RTM.Gum 270
(available from Penford Products). In some other examples, a
suitable starch is nano sized bio-starch, which is commercially
available under the tradename Ecosphere 2202.RTM..
[0051] In some examples, due to strong tendency of re-agglomeration
of the nano particles due to change of ionic strength, the binder
is a non-ionic binder. Examples of such binders are commercially
available, for example, from Dow Chemical Inc. under the tradename
Aquaset.RTM. and Rhoplex emulsions, or are polyvinyl alcohol
commercially available from Kuraray American Inc. under the
tradename Poval.RTM., Mowiol.RTM. and Mowiflex.RTM..
[0052] In addition to the above-described components, the
pre-treatment composition might also contain other components or
additives, as necessary, to carry out the required mixing, coating,
manufacturing, and other process steps, as well as to satisfy other
requirements of the finished product, depending on its intended
use. The additives include, but are not limited to, one or more of
rheology modifiers, thickening agents, cross-linking agents,
surfactants, defoamers, optical brighteners, dyes, pH controlling
agents or wetting agents, and dispersing agents, for example. The
total amount of additives, in the composition for forming the
pre-treatment composition, can be from about 0.1 wt % to about 10
wt % or from about 0.2 wt % to about 5 wt %, by total dry weight of
the pre-treatment composition.
[0053] The pre-treatment compositions are prepared in a liquid
carrier that is used to disperse or solubilize coating composition
components. The liquid carrier can be removed, at least in part,
from the final product (the printable recording media) once the
pre-treatment composition is applied to the substrate, or can
include compounds that remain as solids when a portion of the
carrier is removed, through drying. The liquid carrier can include
one or more of water, co-solvents, surfactants, viscosity modifying
agents, inorganic compounds, pH control agents, deformers, or the
like. The primary function of the carrier is to dissolve and/or
carry the solids or other components that are to remain on the
media substrate as a coating, and for example, provide a carrier
that will suitably carry all the components in the composition and
help them uniformly distribute on the media surface. There is no
specific limitation on selection of the carrier components, as long
as the carrier as a whole has the function described above. In some
examples, the pre-treatment composition comprises a liquid carrier
that includes water.
[0054] The composition or pre-treatment composition of the present
disclosure can be considered as a coating composition since it can
be applied to various media to improve, for example, printing
characteristics and attributes of an image. In some examples, the
pre-treatment composition is a coating composition that is going to
be applied to a media substrate.
[0055] The present disclosure further refers to a printable
recording media that comprises a media substrate and a
pre-treatment composition (or coating composition). Such
pre-treatment composition comprises aggregated nano-sized inorganic
pigment particles, polymeric organic particles having particles
size in a ratio of 100:1 to 1000:1 by comparison with the size of
aggregated nano-sized inorganic pigment particles, an ink absorber
and a polymeric binder. The pre-treatment composition is applied to
a media substrate in order to form a printable recording media on,
at least, one side of the substrate. In some examples, the
pre-treatment composition is applied to an "uncoated" substrate. By
"uncoated", it is meant herein that the media substrate has not
been treated or coated by any composition and that the
pre-treatment composition is applied directly on the substrate that
constitutes the media.
[0056] As illustrated in FIG. 1, the printable media (100) contains
a substrate (110) that supports pre-treatment composition or
coating (120) and that acts as a bottom substrate layer or
supporting base. Such substrate, which can also be called base
print media substrate or base substrate or supporting substrate,
contains a material that serves as a base upon which the
pre-treatment composition will be applied in order to form a
coating layer. The substrate provides integrity for the resultant
printable media. The amount of the pre-treatment composition, on
the media, in the dry state, is, at least, sufficient to hold all
of the ink that is to be applied to the media. The basis weight of
the print media substrate is dependent on the nature of the
application of the printable recording media where lighter weights
are employed for magazines, books and tri-folds brochures and
heavier weights are employed for post cards and packaging
applications, for example. The substrate can have a basis weight of
about 60 grams per square meter (g/m.sup.2 or gsm) to about 400
gsm, or about 100 gsm to about 250 gsm.
[0057] In some examples, the substrate is a paper base substrate.
The media substrate can also be a photo-base paper, an uncoated
plain paper or a plain paper having a porous coating, such as a
calendared paper, an un-calendared paper, a cast-coated paper, a
clay coated paper, or a commercial offset paper. The photobase may
be a paper that is coated by co-extrusion with a high- or low-
density polyethylene, polypropylene, or polyester on both surfaces
of the paper.
[0058] The substrate may include any materials which can support a
coating composition, for example, natural materials (such as a base
including cellulose fibers) or synthetic material, (such as a base
including synthetic polymeric fibers) or non-fabric materials (such
as a polymeric film) or a mixture of them. The substrate material
has good affinity and good compatibility for the ink that is
applied to the material. Examples of substrates include, but are
not limited to, natural cellulosic material, synthetic cellulosic
material (such as, for example, cellulose diacetate, cellulose
triacetate, cellulose propionate, cellulose butyrate, cellulose
acetate butyrate and nitrocellulose), material including one or
more polymers such as, for example, polyolefins, polyesters,
polyamides, ethylene copolymers, polycarbonates, polyurethanes,
polyalkylene oxides, polyester amides, polyethylene terephthalate,
polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl
acetal, polyalkyloxazolines, polyphenyl oxazolines,
polyethylene-imines, polyvinyl pyrrolidones, and combinations of
two or more of the above. The media substrate can be a paper base
including paper, cardboard, paperboard, paper laminated with
plastics, and paper coated with resin. The substrate may include
polymeric binders. Such polymeric binder may be included, for
example, when non-cellulose fibers are used.
[0059] In some examples, the substrate is a cellulose based
substrate, meaning thus that it contains cellulose. The cellulose
base could be made from pulp stock containing a fiber ratio
(hardwood fibers to softwood fibers) of 70:30. The hardwood fibers
have an average length ranging from about 0.5 mm to about 1.5 mm.
These relatively short fibers improve the formation and smoothness
of the base. Suitable hardwood fibers can include pulp fibers
derived from deciduous trees (angiosperms), such as birch, aspen,
oak, beech, maple, and eucalyptus. The hardwood fibers may be
bleached or unbleached hardwood fibers. Rather than virginal
hardwood fibers, other fibers with the same length, up to 20% of
total hardwood fiber content, can be used as the hardwood fiber.
The other fibers may be recycled fibers, non-deinkable fibers,
unbleached fibers, synthetic fibers, mechanical fibers, or
combinations thereof. The softwood fibers have an average length
ranging from about 2 mm to about 7 mm. These relatively long fibers
improve the mechanical strength of the base. Suitable softwood
fibers can include pulp fibers derived from coniferous trees
(gymnosperms), such as varieties of fir, spruce, and pine (e.g.,
loblolly pine, slash pine, Colorado spruce, balsam fir, and Douglas
fir). The fibers may be prepared via any known pulping process,
such as, for example, chemical pulping processes. Two suitable
chemical pulping methods include the kraft process and the sulphite
process.
[0060] The fibers of the substrate material may be produced from
chemical pulp, mechanical pulp, thermal mechanical pulp, chemical
mechanical pulp or chemical thermo-mechanical pulp. Examples of
wood pulps include, but are not limited to, Kraft pulps and sulfite
pulps, each of which may or may not be bleached. The substrate may
also include non-cellulose fibers. The pulp used to make the
cellulose base may also contain up to 10 wt % (with respect to
total solids) of additives. Suitable additives may be selected from
a group consisting of a dry strength additive, wet strength
additive, a filler, a retention aid, a dye, an optical brightening
agent (i.e., optical brightener), a surfactant, a sizing agent, a
biocide, a defoamer, or a combination thereof.
[0061] The pre-treatment composition or coatings according to the
present disclosure can be useful for a number of different types of
media. However, it is particularly beneficial when used with
aqueous-based inkjet inks to print upon porous commercial media.
Porous commercial media is sometimes referred to as "open cell"
commercial media because the surface is porous and tends to readily
absorb ink. One example of such as commercial media is known as
kraft liner paper made of "Kraft" pulp. Such kraft liner papers are
produced from a chemical pulp produced in a "kraft process" or a
"sulfate process." With this process, wood is converted into wood
pulp after removing lignin using chemical treatment. This provides
a paper having an excellent strength and can be usable in a number
of applications including wrapping papers, corrugated fiberboard,
and packaging papers. Open cell paper may be bleached to provide a
white appearance. Formulating aqueous inkjet ink for printing
directly on standard open cell papers can be challenging. The use
of the present pre-treatment coatings provide a treated surface
that can receive inkjet inks and provide a print that is durable
and of high color gamut.
[0062] In some examples, according to the principles described
herein, a method of making a printable recording media comprising a
substrate (110) and a coating layer (120) is provided. Such coating
layer results from the application of the pre-treatment
composition, as described herein, that comprises aggregated
nano-sized inorganic pigment particles, polymeric organic particles
having particles size in a ratio of 100:1 to 1000:1 by comparison
with the size of aggregated nano-sized inorganic pigment particles,
an ink absorber and a polymeric binder. The method of making a
printable recording media comprises providing a media substrate;
applying a pre-treatment composition to, at least, one side of said
substrate, the pre-treatment composition including aggregated
nano-sized inorganic pigment particles, polymeric organic particles
having particles size in a ratio of 100:1 to 1000:1 by comparison
with the size of aggregated nano-sized inorganic pigment particles,
an ink absorber and a polymeric binder; and drying the
pre-treatment composition in order to obtain a coating layer and a
printable recording media.
[0063] FIG. 3 is a flow chart of a method (200) for making the
printable recording media according to the present disclosure. In
this method, a media substrate is provided (201); a pre-treatment
composition is applied to, at least, one side of the substrate
(202). The pre-treatment composition is then dried (203) in order
to obtain a coating layer that will form a printable recording
media (204).
[0064] The pre-treatment composition is dried to remove the solvent
present in the composition such that the coated matrix is reduced
to an average thickness in the range of about 1 to about 8
micrometers. In some examples, the pre-treatment composition is
applied at a basis weight of about 0.1 gsm to about 10 gsm on side
of the media substrate. In some other examples, the pre-treatment
composition will be applied at a basis weight of about 1 gsm to
about 5 gsm, or at a basis weight of about 1 gsm to about 2 gsm on
side of the media substrate.
[0065] In some examples, the pre-treatment composition is applied
to the substrate (110) on one side (on the image receiving side) of
the substrate. In some other examples, the pre-treatment
composition is applied to both sides of the substrate (110) (on the
image receiving side and on the backside).
[0066] The pre-treatment composition can be applied to the media
substrate by using one of a variety of suitable coating methods
such as, for example, blade coating, air knife coating, metering
rod coating, size press, curtain coating, or another suitable
technique. The blocking layer may be, for example, applied using a
conventional off-line coater, or use an online surface sizing unit,
such as a puddle-size press, film-size press, or the like. The
puddle-size press may be configured as having horizontal, vertical,
and inclined rollers. In another example, the film-size press may
include a metering system, such as gate-roll metering, blade
metering, Meyer rod metering, or slot metering. For some examples,
a film-size press with short-dwell blade metering may be used as
application head to apply coating solution. The non-contact coating
method example, the spray coating, is also suitable for this
application.
[0067] In some examples, after the coating step, the media might go
through a drying process to remove water and other volatile
components present in the coating layer and substrate. The drying
pass may comprise several different drying zones, including, but
not limited to, infrared (IR) dryers, hot surface rolls, and hot
air floatation boxes. In some other examples, after the coating and
drying steps, the coated web may receive a glossy or satin surface
with a calendering or super calendering step. When a calendering
step is desired, the coated product passes an on-line or off-line
calender machine, which could be a soft-nip calender or a
super-calender. The rolls, in the calender machine, may or may not
be heated, and certain pressure can be applied to calendering
rolls. In addition, the coated product may go through embosser or
other mechanical roller devices to modify surface characteristics
such as texture, smoothness, gloss, etc.
[0068] A calendering process can then be used to achieve the
desired gloss or surface smoothness. Calendering is the process of
smoothing the surface of the paper by pressing it between nips
formed in a pair of rollers. The rollers can be metal hard roll,
and soft roll covered with a resilient cover, such as a polymer
roll. The resilient-surface roll adapts itself to the contours of
the surface of the substrate and presses the opposite side of
substrate evenly against the smooth-surface press roll. Any of a
number of calendering devices and methods can be used. The
calendering device can be a separate super-calendering machine, an
on-line calendaring unit, an off-line soft nip calendaring machine,
or the like. In some examples, the calendering is carried out at
room temperature. In some examples, the calendering is carried out
at a temperature ranging from about 50 to about 150.degree. C.
(metal roll surface temperature) and, in some other examples, from
about 80 to about 110.degree. C. The nip pressure can be any value
between about 50 to about 500 KN/cm2.
[0069] The present disclosure refers to a printable recording media
comprising a media substrate and a pre-treatment composition,
applied to, at least, one side of said substrate, that comprises
aggregated nano-sized inorganic pigment particles, polymeric
organic particles having particles size in a ratio of 100:1 to
1000:1 by comparison with the size of aggregated nano-sized
inorganic pigment particles, an ink absorber and a polymeric
binder. The printable recording media can be considered as a coated
printable recording media. The pre-treatment composition forms a
coating layer on at least one side of the substrate. Such printable
recording media can be used in printing method.
[0070] The method for producing printed images, or printing method,
includes providing a printable recording media such as defined
herein; applying an ink composition on the coating layer of the
print media, to form a printed image; and drying the printed image
in order to provide, for example, a printed image with enhanced
quality. In some examples, the printing method for producing images
is an inkjet printing method. By inkjet printing method, it is
meant herein a method wherein a stream of droplets of ink is jetted
onto the recording substrate or media to form the desired printed
image. The ink composition may be established on the recording
media via any suitable inkjet printing technique. Examples of
inkjet method include methods such as a charge control method that
uses electrostatic attraction to eject ink, a drop-on-demand method
which uses vibration pressure of a Piezo element, an acoustic
inkjet method in which an electric signal is transformed into an
acoustic beam and a thermal inkjet method that uses pressure caused
by bubbles formed by heating ink. Non-limitative examples of such
inkjet printing techniques include thus thermal, acoustic and
piezoelectric inkjet printing. In some examples, the ink
composition is applied onto the recording media using inkjet
nozzles. In some other examples, the ink composition is applied
onto the recording method using thermal inkjet printheads.
[0071] In some examples, the printing method as described herein
prints on one-pass only. The paper passes under each nozzle and
printhead only one time as opposed to scanning type printers where
the printheads move over the same area of paper multiple times and
only a fraction of total ink is used during each pass. The one-pass
printing puts 100% of the ink from each nozzle/printhead down all
at once and is therefore more demanding on the ability of the paper
to handle all of the ink in a very short amount of time.
[0072] As mentioned above, a print media in accordance with the
principles described herein may be employed to print images on one
or more surfaces of the print media. In some examples, the method
of printing an image includes depositing ink that contains
particulate colorants. A temperature of the print media during the
printing process is dependent on one or more of the nature of the
printer, for example.
[0073] The printed image may be dried after printing. The drying
stage may be conducted, by way of illustration and not limitation,
by hot air, electrical heater or light irradiation (e.g., IR
lamps), or a combination of such drying methods. In order to
achieve best performances, it is advisable to dry the ink at a
maximum temperature allowable by the print media that enables good
image quality without deformation. Examples of a temperature during
drying are, for example, from about 60.degree. C. to about
205.degree. C., or from about 120.degree. C. to about 180.degree.
C. The printing method may further include a drying process in
which the solvent (such as water), that can be present in the ink
composition, is removed by drying. As a further step, the printable
recording media can be submitted to a hot air drying systems. The
printing method can also encompass the use of a fixing agent that
will retain with the pigment, present in the ink composition that
has been jetted onto the media.
[0074] The present pre-treatment composition can be used in
conjunction with an inkjet ink. Such inkjet inks may include a
colorant dispersed or dissolved in an ink vehicle. As used herein,
"liquid vehicle" or "ink vehicle" refers to the liquid fluid in
which a colorant is placed to form an ink. Ink vehicles are well
known in the art, and a wide variety of ink vehicles may be used
with the systems and methods of the present disclosure. Such ink
vehicles may include a mixture of a variety of different agents,
including, surfactants, solvents, co-solvents, anti-kogation
agents, buffers, biocides, sequestering agents, viscosity
modifiers, surface-active agents, water, etc. Though not part of
the liquid vehicle per se, in addition to the colorants, the liquid
vehicle can carry solid additives such as polymers, latexes, UV
curable materials, plasticizers, etc. The colorant discussed herein
can include a pigment and/or dye. As used herein, "dye" refers to
compounds or molecules that impart color to an ink vehicle. As
such, dye includes molecules and compounds that absorb
electromagnetic radiation or certain wavelengths thereof. For
example, dyes include those that fluoresce and those that absorb
certain wavelengths of visible light. Furthermore, as used herein,
"pigment" generally includes pigment colorants, magnetic particles,
aluminas, silicas, and/or other ceramics, organo-metallics or other
opaque particles. In one example, the colorant can be a pigment.
Ink vehicle formulations can include water, and can further include
co-solvents present in total at from 0.1 wt % to 40 wt %, depending
on the jetting architecture, though amounts outside of this range
can also be used. Further, additional non-ionic, cationic, and/or
anionic surfactants can be present, ranging from 0.01 wt % to 10 wt
%. In addition to the colorant, the balance of the formulation can
be purified water, and the inkjet ink can optionally include a
latex.
EXAMPLES
Ingredients:
TABLE-US-00001 [0075] TABLE 1 Ingredient name Nature of the
ingredient supplier Calcium Chloride Ink absorber Sigma-Aldrich
Disperal .RTM. HP-14 aggregated nano-sized Sasol Co. inorganic
pigment particle Raycat .RTM.78 polymeric organic particle
Specialty Polymer Rhoplex .RTM.K3 polymeric organic particle Dow
Hydrocarb .RTM. H60/90 inorganic pigment particulates Omya Inc.
Dynwet .RTM.800 surfactant BYK Inc. Mowiol .RTM. 40-88 polyvinyl
alcohol (PVA) Kurraray binder
Example 1
Pre-Treatment Formulations
[0076] Different formulations of pre-treatment compositions are
prepared by mixing the different ingredients as listed below in
Table 2. The numbers represent the parts of each component present
in each layer based on 100 parts of dry part of inorganic pigments.
Exp. 4, 5 and 6 are formulation of the pre-treatment compositions
according to the present disclosure. Exp. 1, 2 and 3 are
formulation of comparative examples.
TABLE-US-00002 TABLE 2 Exp. 1 Exp. 2 Exp. 3 Ingredients (comp.)
(comp.) (comp.) Exp. 4 Exp. 5 Exp. 6 CaCl.sub.2 solution -- -- 5 5
5 5 Disperal .RTM. 100 100 -- 100 100 100 HP-14 Hydrocarb .RTM. --
-- 100 -- -- -- H90 Raycat .RTM. 78 -- 5 5 5 10 -- Roplex .RTM. K3
-- -- -- -- -- 5 Mowiol .RTM. 10 10 10 10 10 10 40-88 Dynwet .RTM.
800 1.0 1.0 1.0 1.0 1.0 1.0
Example 2
Printable Recording Media
[0077] A base substrate (i.e. commercial uncoated printing paper)
having a basis weight of 146 gsm is used. The substrate is made of
fiber pulp that contains about 80% hardwood fibers and 20 about %
soft wood fibers. The substrate is made of chemical pulped fibers
and recycled pulped fibers. The substrate also contains about 12 wt
% inorganic fillers (calcium carbonates) that are added to the
fiber structure of the raw base at wet end. The pre-treatment
compositions, as illustrated in the Table 1, are applied to the
substrate using a Mayer rod as the metering device and dried. A
glossing treatment is carried out by using a metal/rubber pressured
roll pair. The printable recording media are then calendered
through a two-nip soft nip calendering machine (at 100 kN/m,
54.4.degree. C. (130.degree. F.)).
[0078] An identical image sequence is then printed on the printable
recording media samples treated with the pre-treatment formation
(Examples 1 to 6). The different recording media samples are
evaluated for different parameters and properties: image quality,
durability of the printed image, dry time and gloss. Such
parameters and properties are expressed in Table 3 below.
[0079] The image quality includes the evaluation of the Color
Gamut, bleeding, coalescence, and print mottle. Gamut Measurement
(Gamut) represents the amount of color space covered by the ink on
the media. Gamut volume is calculated using L*a*b* values of 8
colors (cyan, magenta, yellow, black, red, green, blue, white)
measured with an X-RITE.RTM.939 Spectro-densitometer (X-Rite
Corporation), using D65 illuminant and 2o observer angle. L*min
value testing is carried out on a black printed area and is
measured with an X-RITE.RTM.939 Spectro-densitometer, using D65
illuminant and 2.degree. observer angle. This measure determines
how "black" the black color is. Bleed testing is carried out with a
bleed stinger pattern. 1016 micron lines (or 40 mil, where 1 mil=
1/1000th of an inch) of cyan, magenta, yellow, black, red, green,
blue inks, passing through solid area fills of each color, are
printed and scanned. The bleed is evaluated visually for
acceptability.
[0080] The dry time is evaluated by applying an A4 size uncoated
paper (such as HP Bright white.RTM. paper) on top of each fresh
printing images with all primary and secondary color. A 4 lb roller
is rolling three time on top of the A4 paper, then a timer is
started. The paper is removed every minute until the time that has
no ink get transferred to the A4 paper from the printing image.
This time is recorded as dry time of the media.
[0081] The image durability is evaluated by using an abrasion scrub
tester (per ASTM D4828 method). Both print samples and test probes
are immerse in water or in an organic solvent (409 All Purpose
Cleaner.RTM.). The amount of ink remaining on the printed media is
determined by measurement of the ink OD transferred on test probe.
Good adhesion, upon immersion, will tend not to transfer ink from a
printed image and the black optical density (KOD) will be
maintained (A high OD indicates a worse ink adhesion).
[0082] The Gloss level is determined using a gloss-meter (such as
the BYK Tri-Gloss-meter). The gloss level is reported as percentage
per giving measuring angle such as 60 degree angle gloss. The nip
pressure, refer herein to the pressure applied during the calender
process.
[0083] The results of these tests are illustrated in Table 3.
According to such results, it can be seen that the printable
recording media having the pre-treatment composition according to
the present disclosure provides the best overall performances.
TABLE-US-00003 TABLE 3 Gloss Gloss (number of (500 PSI nip Image
nip pressure) pressure) Image Quality Dry time durability Exp. 1 8
14 Poor (low gamut, poor Good Good (comp.) bleed, high mottle) Exp.
2 12 23 Poor (low gamut, poor Good Average (comp.) bleed, high
mottle) Exp. 3 15 25 Poor (bleed) Poor Poor in wet (comp.) smudge
Exp. 4 13 24 Good Good Good Exp. 5 12 35 Good Good Good Exp. 6 11
30 Good Good Good
* * * * *